Pop CD of the week

Don't go angsty on us, Avril

If anything defines youth, it is the desire to grow up fast. The urge is particularly keen in teenage girls, who apply make-up by the trowelful in an effort to look old enough to get into clubs. Stars are no exception. While older artists seek to hang on to their wild youth with both hands - Courtney Love is a case in point - the young and fancy-free can't wait to prove how mature they are by releasing albums full of introspective, middle-of-the-road angst. Pop's one-time favourite tomboy, Sporty Spice, became Mel C, the serious artiste with a bad case of the Bryan Adams. The appeal of Alanis Morissette - Avril Lavigne's most obvious stroppy femme precursor - declined sharply as hours of therapy were racked up and channelled into song. Frankly, one quails at the prospect of Charlotte Church's forthcoming record.

Adolescence was so two years ago for the former tomboy vixen Avril Lavigne. Her second album turns its back on the school corridor, the mall and the skate park; it re-focuses its gaze on adult relationships and its ear on big soft-rock anthems. The ersatz punkette of Let Go, her 14 million-selling debut, only gets to pogo once on 'I Always Get What I Want', a spiky afterthought. Surrounded by bombastic melodic rock and introspective guitar balladry, Under My Skin's most immediately likable track, 'He Wasn't', at least lists a boyfriend's shortcomings in classic teen terms. Avril's wasted her Saturday waiting for him to call. 'I think it's time to bail,' she sulks, while the classic guitar pop tune slots neatly into a lineage including The Go Gos and Joan Jett. Then there's 'Don't Tell Me', which throws up the last uniquely adolescent scenario of Under My Skin : a tryst with a boy with octopus arms. Lavigne's reaction is rather interesting. However, instead of claiming, as Aaliyah once did, that 'age ain't nothing but a number' (something that suited Aaliyah's much older lover, R Kelly, just fine), Lavigne shoos her suitor off the bed. It's somewhat ironic that Lavigne, once marketed as the anti-Britney Spears, should succeed in peddling sexual restraint where the once-virginal Britney so spectacularly failed.

The remainder of Under My Skin wallows in the sort of womanly self-righteousness that wouldn't sound too out of place issuing from Anastacia's mouth. Sure, there are Linkin Park-ish electronic guitar touches on 'Freak Out', and former Evanescence guitarist Ben Moody lends his bombastic nu-metal lite touch to 'Nobody's Home'. But in her efforts to grow up, Lavigne has mislaid her unique appeal. No one with any grasp of punk rock ever mistook her for an authentic rebel, but Lavigne's fresh-faced petulance had a certain charm. Now she's hellbent on churning out the sort of love-gone-wrong melodramas that are the staple product of every other female artist on a major label.

'Together' charts Lavigne's disillusionment with relationships with the aid of a piano and big stadium riffs. 'Take Me Away' charts her disillusionment with relationships with chunky angst. 'Forgotten' (not, sadly, '4gotten') charts her disillusionment with relationships through... you get the idea.

All this turgid femme-rock shouldn't do her enduring commercial appeal any harm. The quiet / loud break-up strop 'Happy Ending' sounds like a hit single in waiting, and every song here is expertly tooled by Linkin Park producer Don Gilmore to suck in fans of big neo-grunge guitars, as well as Lavigne's core audience. But a look under Lavigne's skin turns out to be rather dull; it reveals a second skin, prematurely aged.

It is, of course, wrong to ask the young to remain so artificially. But the best pop music is often supremely adolescent in its concerns. Eamon and Frankee's reigns at the top of the charts should demonstrate how great immature pop can be. Why did Avril have to go and make things so complicated?

Sign up for the Guardian Today

Our editors' picks for the day's top news and commentary delivered to your inbox each morning.